Effects of Low Molecular Weight Organic Acids on the Forms of Active Aluminum in Tea Garden Soils

Objective Taking brown soil, the main tea garden soil type in Rizhao City, as the research object, the effects of three low molecular weight organic acids (citric acid, malic acid and oxalic acid) on the distribution of active aluminum species in tea garden soil were studied by indoor culture experiments.

Method Taking citric acid as an example, the effects of organic acids concentration and pH conditions on the distribution of active aluminum in soil were studied.

Result Compared with the blank control, all three organic acids could significantly increase the content of Ex-Al in tea garden soil, and the increasing order was citric acid > malic acid > oxalic acid; Organic acids could also increase the content of Or-Al in soil, especially citric acid; With increasing of citric acid concentration, aluminum in the soil could be transformed into Ex-Al and In-Al; The contents of Ex-Al, Or-Al, Hy-Al, Ha-Al in tea garden soil treated with citric acid decreased with increasing pH values.

Conclusion It suggested that low molecular weight organic acids had a significant effect on the content and transformation of active aluminum in tea garden soils. Scientific management of tea gardens and alleviation of soil acidification could reduce the impact of aluminum toxicity on tea plant growth and tea quality.